The present invention relates to a damper device with a one-way function for damping, for example, a rotation of a door in an opening direction and not damping the rotation of the door in a closing direction.
A damper device is generally composed of a housing; viscous fluid filled inside the housing; a rotor rotatably disposed inside the housing and including an axis portion with one part projecting from the housing; and a sealing member for preventing the viscous fluid from leaking through the axis portion of the rotor and the housing. The rotor is provided with a projecting portion having a fluid passage and projecting in an axial direction thereof. A valve is provided on the projecting portion. The valve includes a first fluid passage for reducing a flow of the viscous fluid into the fluid passage of the projecting portion when the rotor rotates in one direction, and a second fluid passage for increasing the flow of the viscous fluid into the fluid passage of the projecting portion when the rotor rotates in the other direction.
Patent Reference: Japanese Patent No. 2581655
In the damper device described above, the valve is disposed to be movable and rotatable. Accordingly, the viscous fluid passes through a gap between the valve and the housing. As a result, it is difficult to obtain a desired braking torque with certain accuracy. Also, the valve receives a large load, thereby causing damage and lowering durability.
In view of the problems described above, an object of the present invention is to provide a damper device capable of generating a braking torque with certain accuracy, and reducing a load on a valve, thereby improving durability.
Further objects and advantages of the invention will be apparent from the following description of the invention.